This invention relates to wireless communication systems. In particular, this invention relates to cellular systems and in particular global system for mobile communications (hereafter xe2x80x9cGSMxe2x80x9d) wireless systems.
GSM wireless systems are widespread. These systems now offer features like caller identification or caller ID, call waiting, call forwarding, and other valuable and useful features. Unfortunately, wireless communication systems are sometimes used to further illegal activities. Knowing the phone numbers called by a GSM mobile station or phone (hereafter xe2x80x9cMSxe2x80x9d) can sometimes be valuable to law enforcement agencies for a variety of reasons. Compiling the phone numbers dialed by the MS is a relatively straightforward task.
On the other hand, recording data about inbound calls to an MS is considerably more difficult than recording outbound calls in part because inbound calls to an MS might enter a wireless network of a wireless service provider through a plethora of paths. Inbound calls to an MS can originate from anywhere.
When a caller dials an MS phone number, call processing software in switching systems operated by telephone service providers, route the call to the wireless service provider. The wireless service provider then routes the call to the wireless subscriber through equipment that comprises the wireless network.
A method and apparatus by which calls to an MS in a wireless network can be recorded and compiled might provide law enforcement agencies with valuable information. It might also allow for improved diagnosis of service complaints. Collecting data on inbound calls to an MS could also provide the capability of screening or intercepting inbound calls from particular numbers.
Accordingly, it is an object of the present invention to provide a method and apparatus to provide inbound call trace capability to a wireless indication network.
There is provided a method and apparatus for collecting data on inbound calls to a wireless subscriber. In a wireless communication system, such as the GSM wireless system, calls to an MS are routed through at least one central switching system, known as a gateway mobile switching center (GMSC) that is operatively coupled to several, mobile switching centers (MSCs). MSCs are spread across the geographic area in which the GSM wireless service is offered. Each MSC provides the GSM wireless communication functionality to the geographic region surrounding the MSC. The GMSC and the MSCs make up the GSM public lands mobile network (PLMN).
A call to an MS in a GSM PLMN is first processed in part by the GMSC querying a central database to identify a particular MSC that the wireless subscriber is closest to. The home location register database (HLR) in a GSM PLMN is a central repository of data pertaining to wireless subscribers. Locating the MS in the GSM PLMN is accomplished in part by the GMSC communicating with the HLR to learn the identity of the subscribers within its coverage area.
Wireless-subscriber-caller data, (i.e. data on calls to a particular wireless subscriber) collected by the GMSC is forwarded to the HLR database for subsequent processing or other presentation or use. The wireless-subscriber-caller data can alternatively be sent to aid other processors for subsequent delivery to the HLR database or some other appropriate database as well.